Right patient. Right drug. Right dose. Right genome. Why genetic diversity is vital for pharmacogenomics
May 30, 2019

Drug development is an expensive business. Not only may it cost hundreds of millions of dollars to successfully bring a drug from concept to market, but the reality is that up to 90 per cent of drugs fail in the early stages of clinical trials. Even if a medicine does reach the point of sale, it probably won’t be effective in all patients with the same condition.

If we are to provide people with the best possible healthcare, the inefficiency of drug development and ‘one size fits all’ approach to treating patients needs to change.

With whole genome sequencing now taking place quickly and relatively cheaply, a lot more data is available on genetic drug targets and their presence or absence in certain people, suggesting whether a drug might be suitable. Variations throughout the genome also affect how quickly drugs are broken down in the body, or whether there might be a higher risk of harmful side effects – a concept known as pharmacogenomics.

Assorted pharmaceutical medicine pills, tablets and capsules over blue background
Right patient, right drug, right dose, right genome. Image licensed from Envato.

Knowing a person’s genetic makeup means that certain treatments be personalised for how they will respond. For some people, this might mean a higher or lower dose of a particular drug. However in some cases, a drug is better off avoided completely because it might cause unwanted side effects or is unlikely to work to treat their condition.

Given recent progress in genome sequencing, pharmacogenomics might seem like a modern scientific discipline, but the concept was actually first recognised by the mathematician Pythagoras around 510 BC. He noticed that some people who ate fava beans (broad beans) developed haemolytic anaemia – a serious condition in which red blood cells start to break down.

But it wasn’t until 1956 that researchers discovered that the underlying reason for the reaction, known as favism, lay in a genetic change that affects the levels of G6PD – an enzyme involved in metabolism that normally protects red blood cells against the harmful effects of chemicals in the beans.

Since then, the field of pharmacogenomics has grown rapidly, and there is an ever-growing list of genetic variations that affect drug dosage, breakdown and effectiveness.

For example, variations in a gene called cytochrome P450 2C9 affect how the body breaks down warfarin, a commonly-used blood thinning drug – meaning that a patient might need a higher or lower dose to prevent dangerous clots forming while reducing the risk of harmful side effects like bleeding.

Pharmacogenomics is vitally important in delivering the benefits of personalised medicine, tailoring treatment to each individual’s genetic makeup in order to bring the most benefits.

Yet, as we’ve pointed out many times before, most of the genomic data that underpins this field has been gathered from people with European ancestry, severely limiting its applicability across a global population.

Asthma is one condition that neatly demonstrates the issue. This disease is most common among people of Puerto Rican or African descent living in the US, but these groups have a poor response to albuterol inhalers compared with patients of European descent. A recent study analysing the genomes of over 1400 children with asthma revealed gene variants linked to a lower drug response, but this has yet to be replicated in further groups of similar patients.

A lack of suitable treatments and pharmacogenomic information for non-white populations can lead to poor health outcomes and puts people at an unnecessary disadvantage.

Genomic information about the likely effectiveness, dosage and side effects of drugs could make a huge difference to someone’s health, but most people have no idea of this potentially life-saving data within their DNA – information that could be gathered with a simple cheek swab or a small blood sample.

That’s why we’re working on solutions aimed at improving diversity in genomic and pharmacogenomics research and widespread access to this information through our upcoming app, ggcME™, to allow everyone to get the treatment that is right for them, wherever they come from and wherever they live.

We’ll be announcing more about ggcME™ soon, so follow us on Twitter for the latest news and updates: @globalgenecorp